the_custom_bicycle

THE CUSTOM BICYCLE

the needs are not met in the standard line, a special custom design can be provided.

Like Cinelli, Schwinn's building and design philosophy stresses rigidity over extreme lightness. For example, since it is difficult to build a good, stiff frame in a large size, Schwinn uses heavier-gauge tubing to achieve stiffness as the size of the frame increases. Extra-heavy chainstays and fork blades are used on all models. On extremely large frames (in excess of 26 inches), straight gauge SAE 4130 chrome molybdenum is used for the down tube and the seat tube. By combining this tubing with a stiffer front fork, Schwinn has been able to overcome a lot of the tracking problems that occur on large frames when riding downhill and riding without hands. Through years of experience Schwinn has opted for rigidity rather than lightness.

Frank Brilando doesn't believe that there's a great difference between the chrome molybdenum tubing and the Reynolds manganese-molybdenum tubing as far as the end product is concerned. He does believe that a little more caution has to be used when working with chrome molybdenum tubings because overheating and rapid cooling will cause more brittleness in the frame joints than with manganese molybdenum. Why does Schwinn use chrome molybdenum tubing more extensively? According to Brilando, "We've found the Reynolds tubing to be very good and there's no reason to change just for the sake of changing. Furthermore, 531 has good acceptance by the public."

Frank Brilando believes that you cannot consider the top tube dimensions by themselves since they are influenced by the other frame specifications. As a rule, top tube length should not be a controlling factor in ordering a custom frame because if, for example, a shallow seat angle is requested (and everything else is constant) a longer top tube will be required. "Top tube length by itself doesn't mean an awful lot unless you tie it into the complete bicycle."

Schwinn is probably the only large manufacturer in the world that makes a top-line touring model. The design of Schwinn's standard line touring model has been tested and retested to insure a safe and comfortable ride. The touring Paramount has a slightly longer wheelbase, due to a longer rear triangle, which distributes the weight of the rider and the touring load more evenly on the frame. Through testing, Schwinn has found that a slightly longer rear end(3/8inch) will transfer some of the weight to the front of

SCHWINN

the bicycle and the better weight distribution will contribute greatly to the safety of the rider. If you know that the 3/8-inch longer stay gives you better weight distribution, what would happen if the rear triangle were lengthened by an additional 5/8 inch? Schwinn's tests have shown that a longer rear triangle will create instability and make the bicycle handling unwieldy. The 3/8-inch longer stay that Schwinn uses is the best compromise.

One of the greatest problems a tourist has to face is riding downhill with the weight of touring packs on the bicycle. Again, Schwinn has performed tests which indicate that the racer shares the problem of instability on downhills, but that his problem is more manageable because he is riding without bulky packs. The downhill problem is exacerbated when carriers and packs are attached to the bicycle, especially, as Brilando notes, "when rear carriers are not anchored solidly. They tend to shimmy and this transfers through the whole bicycle."

To help eliminate this dangerous situation, Schwinn's testing has confirmed that:

1.carriers must be solidly secured to the frame;

2.carriers must be strong enough to support the packs;

3.the packs must securely fasten to the carrier, to insure as little movement as possible;

4.the weight should be distributed in the panniers with the heavy items at the bottom.

If you are going to use front panniers, the same criteria apply. Of course, overloading front panniers will cause a dangerously unstable condition. Although most people seem to be using front handlebar packs, Schwinn has not done any conclusive testing in this area, but Brilando believes "if it is rigidly held, it is not too bad. If it slops around, then you get into instability problems."

The road racing Paramount that Schwinn offers in its standard line is designed for long-distance road races. A special lighter criterium frame is offered but only as a custom order. The same applies to the track frame. The standard Paramount track frame is built for sprints while lighter pursuit frames can be ordered on a custom basis. Although Schwinn uses Reynolds 531DB on all its frames, the tube gauges are heavier than the standard-packaged Reynolds 531DB sets. The reason for the heavier tubing is the belief that frame rigidity is affected more

CHAPTER 18

Profiles of Some

American Frame Builders

Limited, in England (see chapter 5).

The majority of the American builders use Du Pont's Imron paint because of its resistance to chipping. The British, on the other hand, increase the chip resistance of their paints by their methods of applying the paint. While Imron is fairly easy to apply and it requires a minimum of steps, the British processes require several steps. Accordingly, the actual painting of the frames has become a British trademark.

It comes as no surprise that Matt's bicycles have a very British look. He learned the basics from Bob Jackson. Matt's paint process is involved and can best be described in his own words:

Painting is a six-step process beginning with the removal of all oxides from the bare frame by a light sandblasting. The bare frame is then chemically treated with rust-inhibiting bonding agents which eliminate rust problems and also bond the paint film to the metal. The frame is then primed and enamelled with Sherwin-Williams professional paint system. The transfers and the hand lining are done at this time. After the transfers have cured, the frame is finished with a special two-part clear acrylic for added durability and gloss. The paint then cures in about 24 hours and the frame is ready for assembly.

THE CUSTOM BICYCLE

Under the paint job, Assenmacher's frames are orthodox in design and construction. Like the Europeans, Matt does not use a jig for brazing the main triangle. Only the forks and rearstays are brazed in a jig. All Assenmacher frames are silver-brazed and are built personally by Matt. His one assistant handles only the cleanup, sandblasting, and initial paint preparation steps. The decision of which gauge and type of tubing to be used is made after Matt learns the size and weight of the rider, his or her riding style, the ultimate use of the frame, and the rider's individual preferences.

Figure 18-1: Assenmacher putting the finishing touches on one of his frames.

PROFILES OF AMERICAN BUILDERS

Assenmacher, who has been building frames since 1973, currently builds about two a week. In addition to his custom frame building, he has a constant supply of frame repairs for other competitive brands. His frame repair business is strong because people have learned of his quality workmanship. Furthermore, there are proportionately fewer frame builders in the Midwest than in the West.

Assenmacher is eager to please his customers and he will build racing or touring bicycles and tandems. He is particularly cognizant of the needs of the tourist and will supply brazed-on frame fittings in any configuration desired by the customer. Although he is only 27 years old, he has been an enthusiastic cyclist for over half of his life. Currently he is succeeding in providing the kind of service that is difficult to duplicate when dealing overseas, while at the same time, is building a bicycle that compares favorably with those built by the British.

amine their complete production for a year without finding two identical frames. Like his compeititors, Bill Boston specializes in matching the individual needs of a rider. He has taken the art of properly sizing the frame one step further, however. He has constructed an "adjustable" frameset with variable seat angles, top tube height, bottom bracket height, and top tube lengths. After personally determining the basic parameters of the "ideal" frame with the customer astride the adjustable frame, Bill attempts to determine the individual needs of the customer—a racing or touring frame, for instance.

Like many of the popular builders, Bill Boston is young. He's in his early thirties. He started building frames, on a part-time basis, in 1972. By 1975, the demand for his products reached the point where he decided to make bicycle frame building his sole livelihood.

After high school, Bill worked for a short time at Du Pont and then joined the navy. For six months of his navy experience he

PROFILES OF AMERICAN BUILDERS

Figure 18-3

pointers. His strong technical background left him disenchanted with the British builders and their reliance on what Bill felt was "feel" rather than technology.

Although Bill Boston's annual production is only approximately 50 frames, or less if there is a high proportion of tandems, the number is not a true indication of his potential. Much of his time is devoted to his hand-manufacture of special handlebar stems (each one takes 12 to 14 hours to produce}, integral alien key seat tube fittings, and custom racks for touring. Bill likes to think of himself as a craftsman and his concern for the quality of his products is greater than the profit associated with the venture.

Initially, all Bill Boston frames were jig-built with brass, but he has since switched to silver. The switch was made after Bill